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Questions tagged [geotechnical-engineering]

Geotechnical Engineering is a branch of Civil Engineering focused on the engineering properties and behavior of natural and engineered geomaterials (soils and rocks), as well as the design and construction of foundations, earth dams and levees, retaining walls, embankments, underground structures and tunnels.

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Hoe functioneert de Blum-methode in detail?

i dont understand how the method of blum works can someone explain it to me if you are dutch it would be a big help although english works aswell.
Idries Tanouti's user avatar
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When running a consolidation test (astm D2435) what is considered a small enough amount of consolidation to move to the next load?

I have been reading my text book and the astm for lab and it talks about the material finishing consolidation (usually 24 hours per load. In the test method it does not show an acceptable amount to ...
HingedHD's user avatar
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If drilling to the mantle is too hot for drills and too hard for millimeter waves, why not use positrons?

Would it be possible to make a millimeter sized hole which extends down to the mantle, and fill it in with a heat sink, to draw the heat upwards to a mine for steam production and then power?
Jais's user avatar
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1 answer
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How does the maintain load test work?

A project site in my company is currently working on testing the settlement of our piles using the maintain load test, so my boss is asking me to find out some information on this. In particular, he ...
Kevin Halim's user avatar
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1 answer
47 views

why are horizontal and vertical stresses on an element in soil mass considered as principal stresses?

Despite the fact that there are shear stresses also involved while considering deformations in soil why are the horizontal and vertical stresses on an element as shown in below figure considered as ...
inquisitive learner's user avatar
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What are some static and dynamic characteristic we can get from probe inclinometers?

I'm currently doing a work about probe inclinometers but I need to know which soil characteristics we can ger from the inclinometers.
Isaac Gordillo's user avatar
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1 answer
262 views

Geotechnical engineering: The $\phi=0$ concept

I am reading B.M. Das' book: Principles of Geotechnical Engineering, 6th edn. In the chapter concerning shear strength of soil the $\phi =0$-concept is introduced.$\phi=0$-concept" /> In an ...
Erik Eriksson's user avatar
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1 answer
36 views

Is internal friction angle isotropic in soil?

I am studying geotechnical engineering and specifically the chapter in B.M. Das book of the same name, 6th edition. On the topic of shear forces, reference to internal friction angle, $\phi$ is made. ...
Erik Eriksson's user avatar
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453 views

Relationship between inclination of failure plane and angle of internal friction in soil

I am reading Geotechnical engineering by B.M. Das, 6th edition. In the chapter on shear strength of soil this is stated: "It can be shown that $2\theta = 90 + \phi' $ " where $\theta$ is the ...
Erik Eriksson's user avatar
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2 answers
124 views

What is the largest diameter a vertical mine shaft may have in bedrock?

What are the design constraints to the diameter of a mine shaft in bedrock, considering the pressure of the ambient rock, its compression strength, the width of the liner, and its compression strength?...
tourist's user avatar
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What is the best way to disrupt rock slope landslides?

From my understanding, landslides and other erosion occurs along various natural formations in the geologic bed, such that all the organic material above some geologic strong point fails, and all the ...
hannasm's user avatar
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Would it be possible to generate electricity from continental drift?

It definitely wouldn't be practical compared to other sources of energy, but given currently plausible technology, would it be theoretically possible to use the movement of tectonic plates (as in ...
A Curious Inquirer's user avatar
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1 answer
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what kind of expert can analyze drought effect on rock fall risk?

I'm discussing safety with a team doing endangered plant conservation work in a small very narrow gulch with walls hundreds of feet high. We see evidence that rocks fall often, and would like to ...
J. Win.'s user avatar
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3 answers
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What is this geotechnical mechanical drop device and what does it measure?

I encounter this device from youtube. The engineer drops a weight on the device to measure something. After they doing some earthmoving. https://youtu.be/r5Kj4-VqGVs?t=474
Kyrielight's user avatar
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Soil movement due to open cut excavation

When I model an open up excavation in the computer model, I found that when the surcharge applied on slope is long enough , the soil movement (downwards under the surcharge region) is lower. When I ...
gx6336's user avatar
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2 answers
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Water flow near dam geomechanics

I have basic Geomechanics question , one of the drawing is true and the others are wrong , which one ? , explain why the others are wrong . First one wrong because the number of squares are not equal ...
Razi Awad's user avatar
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1 answer
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Relation of shear strength to bearing strength of soil by formula

From formulas: Shear Strength: $τ = c+ σ'\cdot sin\phi$ Bearing strength such as: $1.3 cN_c+ qN_q + 0.4B_γN_γ$ Now I know that bearing capacity decreases as the shear strength of soil decreases. ...
upstream's user avatar
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How to make top of rebar cage of CIP pile exposed

A long time ago I saw that when cast in place piles were poured, the rebar cage was lowered all the way to the hole and the concrete was cast. After the concrete hardened, the soil around the top of ...
upstream's user avatar
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Effect of area spring at slab on column

Say that a simple building is supported by 4 columns , the column sitting on base slab. I assigned some sort of area spring to the base slab. When the area spring assigned is higher, this cause the ...
utk2366's user avatar
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2 answers
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Civil Engineering - Detailing of free draining backfill and modelling of hydrostatic pressure in retaining walls

It is considered best practise to specify free draining backfill material (eg gravel) to be placed immediately behind a retaining wall. Supposedly, this alleviates hydrostatic pressure on the wall, ...
thevincent0001's user avatar
2 votes
3 answers
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how much force is required to drive a fence post 2ft into soil or sand using a hydraulic press?

I'm building a post driver for the farm and it got me thinking: what force is required to drive a 6ft(1.8 m) 4 inch (100 mm) post 2 ft into the ground? I'm wondering how different soils affect driving ...
Sharaf's user avatar
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Is VLF-EM scanning for fractures a valid way to find groundwater for a well?

I need to choose where to drill an agricultural well. I am trying to get as much water as possible (at least 100 gpm). I am considering hiring a guy who claims to be able to find water using a device ...
Diogenes Creosote's user avatar
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1 answer
59 views

Tunnel lining vs structural support

Is tunnel lining the same thing as tunnel structural support? And then also there is always the initial and final lining? Are three all different things? And how do they relate to waterproofing? It ...
upstream's user avatar
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Distance of raft foundation outwards

Can you tell me (for USA) which code (or standard or guide) and in it where exactly I can see the distance required for the raft foundation, as far as how much it should extend horizontally beyond the ...
upstream's user avatar
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3 votes
3 answers
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Low pile capacity during pile driving

When driving piles, the resistance from the soil is constantly measured. What happens when the expected resistance values from the soil are not obtained? For a single pile or for multiple piles? What ...
upstream's user avatar
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1 vote
1 answer
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When settlement criteria of a foundation is satisfied, bearing criteria is also automatically satisfied?

We design the foundations to settlement criteria than bearing correct? Because settlement criteria is stricter? I mean, can there be an example where the settlement criteria is satisfied but bearing ...
upstream's user avatar
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1 vote
1 answer
360 views

Effect of overburden pressure on the skin friction pile capacity

In a given soil, the lateral effect of overburden pressure is constant with depth, as in $p=qk$, where: $p$: lateral pressure effect, $q$: overburden pressure $k$: soil lateral pressure coefficient. ...
upstream's user avatar
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Missing items in geotechnical reports [closed]

In your experience, what items that should be in geotechnical reports are sometimes missing, and what do you do in that case, can you provide example? Do we look at codes or make best guess and based ...
upstream's user avatar
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2 votes
2 answers
5k views

What is the meaning of these two inverted triangle water table symbols in a borehole record?

Consider the borehole record below (in particular the Water Depth column). There is a white inverted triangle at a depth of 3.20 m. What is the meaning of this symbol? The white inverted triangle ...
egg's user avatar
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1 answer
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The best foundation type?

What are the best foundation type for a construction in the city and earthquake prone area? If bored pile foundation is the best, which type is the best, square, circle? what are the considerations of ...
Cindy.Karina9's user avatar
2 votes
1 answer
703 views

Drained and undrained shear strength of clay correlated?

When we measure the undrained strength of clay via CPT or triaxial test for instance, is there a way to correlate this to drained strength? How? I ask because measuring drained strength takes very ...
upstream's user avatar
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1 vote
2 answers
133 views

Does Eurocode allow use of Robertson chart to determine soil type based on CPT results?

It seems that use of the Robertson charts (Robertson, P.K. [1990] " Soil Classification using the cone penetration test" Canadian Geotechnical Journal 27(1), 141-8) to classify soil type based on CPT ...
user32882's user avatar
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1 answer
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How much does the weight of urban structures (buildings) affect the compaction (permeability, porosity, density) of alluvial sediments below a city?

Original Question was here. I live in Van, Turkey. Van City is situated on an alluvial plain beside Lake Van. General geological structure of the area can be seen on pages 43-44 in this conference ...
serekani's user avatar
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1 answer
77 views

Modelling Soil in a Scale Model

I'm building a scale model for a proposed construction project. Is it possible to simulate foundations operating in soil in a scale model? What do people typically use?
xirt's user avatar
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1 vote
2 answers
203 views

what means Probablity of event excedence of so many years

I like to know about occurrence of earthquake events when we say that earthquake of 0.5 g will occur in 50 years in excedence of.
Hussain Ahmad's user avatar
1 vote
1 answer
9k views

At what level is the Grade Beam most effective at pile cap level or at Slab-on-grade level?

The primary two functions of a Grade/Tie Beam in spread footing and/or pile caps foundation system is to support the Slab-On-Grade (S.O.G) and/or to take the moment from eccentric footing (or moment ...
J.Daou's user avatar
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2 answers
2k views

Difference between Allowable Bearing capacity Service and Ultimate?

When we calculate the dimension of a foundation we always use the allowable SERVICE bearing capacity (lets call it qs) and all the necessary checks are based on this value qs. My question is why does ...
J.Daou's user avatar
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3 votes
0 answers
44 views

What is the effect of ageing on preconsolidation pressure?

Preconsolidation pressure is the maximum effective vertical overburden stress that a particular soil sample has sustained in the past. How far in the past does the soil remember its loading/the ...
Bibek Panthi's user avatar
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0 answers
26 views

Wave train 200 m/s meaning

I ran a 60 m seismic line. Energization with hammer. 12 (10 hz vertical 5 m spaced) geophones and 5 shots (15 m spaced). Record length 0.5 s. Thanks to a borehole near a estrata of gravelly silt man-...
Carlos Javier's user avatar
1 vote
1 answer
60 views

Drucker-Prager Model Parameters, a Proper Choice

My task is to write a code from scratch for 3D elastoplasticity, namely a DP model (see for example DeSouza Neto, et al., 2008, Chapter 8) having yield surface $$ f(\mathbf{\sigma},c) = \sqrt{J_2(\...
matte's user avatar
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1 answer
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Soil mechanics-Geotechnical engineering [closed]

Which is more economical to improve or change the soil that is used to build a structure? my answer is that it depends on each case, but I would like to get more information, or where to search about ...
Just believe 's user avatar
2 votes
2 answers
83 views

Why are home geothermal systems usable anywhere in the U.S. but industrial geothermal plants limited in geographical use?

Geothermal systems are used in regions across the U.S. for home use, but industrial geothermal plants are only used in areas where subteranian temperatures are very high. Why is this? https://en....
Hypnos Stratagem's user avatar
1 vote
2 answers
620 views

Is it possible to calculate Young's Modulus of Clay from load-controlled tests?

I'm trying to get the compressive strength (and Young's modulus) of a clay sample. The method I found is called 'Unconfined Compressive Strength of Cohesive Soil'. According to ASTM D2166M, I have ...
Mohammad's user avatar
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What diameter of particles will result in a blocked borehole?

My mine is looking to install a 600 mm open borehole to drop particles up to 150 mm through. It's a 320m shaft to drop ballast down to save time compared to using the drift. When it gets blocked ...
Scott's user avatar
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1 vote
1 answer
325 views

Thai Cave Rescue- Why the narrow portions are not being broadened?

Tham Luang cave rescue incident is taking combined effort of Engineers throughout the world. Various news media is telling currently it is not possible to pass more than one person through some very ...
user avatar
1 vote
2 answers
478 views

Liquid Limit of Soil through Atterberg Tests

My lab is evaluating the liquid, plastic, and shrinkage limits of some soil samples and we are following this video provided by the Missouri University of Science and Technology. The video indicates ...
Environmental Enthusiast's user avatar
3 votes
0 answers
38 views

The use of Theis equation based on time

The storage coefficient (s) for artesian basin can be determined by the following equation (Theis equation): $$s=\frac{Q}{4\pi T}\int_{\frac{r^2S}{4Tt}}^\infty\frac{e^{-u}}{u}du$$ Does this ...
Gevor Hakobyan's user avatar
4 votes
1 answer
2k views

How do you convert "kps" to Pounds per Square Foot (psf)? [closed]

I'm looking at a soil bearing capacity report, which has a column labeled "kips" and the values are followed by "kps". A "kip" is 1000 pounds, but I'm not sure how to convert from "kps" to psf. The ...
Nick's user avatar
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8 votes
1 answer
882 views

Why is this construction site pouring gravel over a wire mesh, and then covering it with dirt?

My office is afforded a prime view of a construction project where the workers are currently covering the leveled ground in a wire mesh, raking gravel across the entire mesh, and then covering that ...
TylerH's user avatar
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2 votes
1 answer
197 views

Are pumps used in geothermal systems

The water held underground in a geothermal system is under high temperature and pressure. Are pumps used to raise the very hot underground water to the surface or does the water rise under its own ...
Hypnos Stratagem's user avatar